An anchor is not just for the coast

Plenty of inland boaters carry an anchor that has never left its locker. That is fine, right up to the moment it isn't. A dropped throttle cable on the Trent, a failed gearbox on the tidal Thames, a sudden squall on a broad Norfolk water — these are the days when a properly sized anchor, ready at the bow, stops being a piece of kit and starts being your brakes.

The catch is that inland waters are not the sea. What holds beautifully on a shingle spit off the Solent may skate across a silty canal bed, and the anchor that saves you on the Ouse might be useless in a shallow, weed-choked dyke. The anchor you choose has to match the water you actually cruise, not the water in the brochure.

What lies beneath: canal beds and river beds are different

Before spending money, think about what your anchor has to bite into.

• Canal beds are often puddled clay or compacted silt, sometimes lined with stone or concrete. An anchor may not penetrate at all, and the channel is usually too narrow to swing to a proper scope.
• Non-tidal rivers vary wildly: gravel and chalk on some, deep soft mud on others, with weed beds and sunken branches in between.
• Tidal rivers give you the best holding — firm mud, sand, gravel — but the current reverses twice a day and can run hard in a lock cut or a bridge reach.
• Broads and fenland waterways are typically shallow mud over peat, which suits a heavy weight more than a fluke anchor.

Be realistic about this: on most narrow canals, anchoring in the navigable channel is neither sensible nor welcome. You moor. An anchor isn't going to save you there — but on the rivers and broads it will.

Matching anchor type to your usual cruising ground

• Flat or Danforth-style anchors are the traditional choice for river work. They bite well in sand and firm mud, store flat, and hold decently in a straight pull. They can struggle in soft silt or heavy weed, and they dislike fouling.
• Claw or Bruce-type anchors are the all-rounder for mixed river beds. They set readily, cope with a change of direction when the tide turns, and are forgiving of mud. A popular choice for river cruisers and narrowboats that venture onto tidal reaches.
• Plough and scoop anchors hold strongly in sand and gravel but need a decent length of chain to work properly, and they can be reluctant to set on a hard canal bottom.
• Grapnels are for rocky or weedy ground where nothing else will bite. They hook rather than bury, so treat them as a short-stay solution.
• Mud weights suit the Broads, shallow fenland rivers and anywhere you simply want to slow the boat and hold position. They are not designed for a strong tidal stream.

As a rough starting point for a 45 to 60 foot narrowboat or river cruiser, a 15 to 20 kg anchor with 8 to 10 metres of 10 mm chain and 30 metres of 16 mm nylon warp is a sound baseline. Fish bigger if you regularly run tidal water or a fast-flowing river.

Ground tackle: chain, warp and weight

Boaters often overspend on the anchor and under-spend on everything attached to it. The chain is what keeps the shank low and lets the flukes dig in; without it, even a good anchor drags.

• Chain: at least the length of the boat, more if you can stow it. Ten metres is a sensible minimum on a river-capable inland boat.
• Warp: nylon, with some stretch to absorb snatching. Thirty metres lets you lay out five to seven times the depth in typical river conditions.
• Scope: aim for 5:1 minimum, 7:1 on a tidal river. More scope means better holding, every time.
• Fittings: a proper bow strong point, a rated shackle, and the bitter end made fast so you can still retrieve everything — or cut it free in an emergency.

Deploying it properly, and getting it back

An anchor that is buried under a bunk, still zip-tied to its bracket, is decoration. Keep it on a roller at the bow, shackled on, warp flaked and ready.

• Stop the boat, or bring it to a slow sternway, before you lower the anchor. Never throw it.
• Lower it hand over hand from the bow, paying out as the boat drifts back, so the chain lies along the bottom rather than piling on top of the anchor.
• Once you have your scope, take a turn and let the boat snub up gently. If it drags, pay out more warp before you consider resetting.
• Note two transit marks on the bank and check them every few minutes. That is how you know you are holding.
• To recover, motor slowly forward over the anchor while someone hauls the slack in, then break it out vertically.
• In rocky or foul ground, rig a tripping line with a small buoy so you can pull the anchor out backwards.

Practise before you need it

Pick a quiet, known stretch — a wide river reach with good holding and no traffic — and spend an hour setting and recovering the anchor in daylight. Learn how the boat behaves, how much scope you need, and how long the whole job takes. Two people working together make it far easier than one.

Do that a few times a season, and the day the engine falters on a tidal river, you will already know exactly what to do.